1. Field of the Invention
The present invention relates to a cordless telephone system, and in particular, to a communication method in a cordless telephone system.
2. Description of the Related Art
A cordless telephone system is typically composed of a base unit which is connected to a central office line and a portable unit for communicating with the base unit or with a different wired/cordless telephone while a user roams within a predetermined area. Though one portable unit is generally registered with a base unit, the number of registered portable units per base unit can be increased. That is, in addition to a portable unit provided with the base unit, another portable unit can be purchased and registered with the base unit. In this manner, two or more portable units are registered with a single base unit. Use of a portable unit registered with a base unit allows a user to conveniently communicate without moving to the location of the base unit.
Many homes and offices currently use two or more telephones by connecting the telephones in parallel to a single telephone line or by connecting the phones to different telephone lines. In the first case, the telephones are assigned an identical phone number so that only a single call can be performed by a subscriber at a given time. In the latter case, each telephone line is assigned its own phone number, and each line can support a call.
In using a cordless telephone system in the above cases, one or more portable units are registered with a base unit and a call with a portable unit is performed via the base unit. Therefore, when two or more portable units are registered to a base unit, a first user cannot make a call with a portable unit when the base unit is engaged in a call from a second user with another portable unit. This results in inconvenience to the user who must wait to initiate a call or perform the call on another telephone system.